i got back my spectrum oil report today. this is the back side with the past history which is very useful. every 30 hrs i am either cutting open the oil filter or doing oil testing.
Rocketbob,
You are expecting the wrong thing from oil analysis.
You see one size particle in the filter, OA looks at microscopic particles, up to only about 10 or 15 microns. OA tells you you have unusual wear going on, such as a bearing going bad. It will not tell you about a catastrophic failure, such as a part breaking. What you are looking for in OA is a change from previous samples and an indicator of a problem developing.
I wouldn't say it is worthless based on the not finding the wrong failure.
When you have a slow wear item going bad, it can be useful. I normally say it takes three bad reports (that don't have major alarming changes) to make a trend and something that should be investigated very seriously. Some thing like a cam lobe going bad normally shows up with increase iron followed by high iron and high aluminum with the iron levels getting higher and higher each time. exhaust valve and guide wear normally shows as high nickel. To me, oil analysis is a trending tool, not a tool that will tell you engine failure is imminent. It may tell you that you have a hole in the induction system with high silicon, valve stem and guide wear with high nickel or that you aren't flying enough with high iron. Sometimes it will warn you that something is going on and you check it out, find the problem, and save some money by finding it early before it turned into something more major. Sometimes it gives you high readings, you check everything and can't find anything and then all it does is give you anxiety until the levels go back down to the averages.Does anyone reading this thread have a story about a time where oil analysis actually caught something? I'd be curious to hear where it's made the difference. Just looking at the one posted above, seems like lots of 'normal' variation, so how would you interpret a bad result?
i started this post and believe that not many use OA. when my first engine started getting up past TBO i started using OA. the hobbs finally when to 3,150 hrs[ = to 2,600 tach time] before the cam lifter started making metal. the two things i was concerned with was a valve head breaking off and the cam/ lifter wearing out. i did the wobble tests, comps over 74/80, and rolled the dice on the valves holding out. i finally picked up and increase in iron on a OA, 25 hrs later i cut open the oil filter and my jaw dropped. it was loaded with fine metal pieces. when i put a magnet on it it looked like a fuzz ball. i was all ready and prepared to sell the old engine and buy a new thunderbolt from lycomig which i did. OA is not for everyone but i enjoy seeing the results every 60hrs now. here are a few picks of the final oil filter. safe flying hope you make TBO too. turboDoes anyone reading this thread have a story about a time where oil analysis actually caught something? I'd be curious to hear where it's made the difference. Just looking at the one posted above, seems like lots of 'normal' variation, so how would you interpret a bad result?